Process of producing fast dyeings and the dyed fiber obtained thereby



Patented July 8, 1941 UNITED STATES PATENT" OFFICE PROCESS OF PRODUCINGFAST DYEINGS AND THE DYED FIBER OBTAINED THERE- Werner Kirst, Konigstenin Tannus, and Wolfgang Alt and Hans Krzikalla, Ludwigshafen-on-the-Rhine, Germany, ,assignors to General Aniline & Film Corporation, acorporation of Delaware N 0 Drawing. Applicati0n-September 24, 1938, Se-

rial No. 231,594.

In Germany September 24, 1

comma, (c1. s.-21)

The present invention relates to the production of fast dyeing-s and tothe dyed fiber obtained thereby.

We have found that dyeings o-fgood properties of fastness, especially ofhigh 'fastness -to wet processing may be obtained by applying to thetextile fiber in a feebly alkaline, neutral or feebly acid bath awater-soluble azo-dyestuff containing in the molecule an amino-groupcapable of .being diazotized and ahydroxyl group rendering couplingpossible, then diazotizing the dyestuff on the fiber and causing it tocombine with itself. The self-coupling may be performed or completed,for instance, by adding to thediazobath an agent neutralizing the acidor having an alkaline .action, after .the diazotization is finished, orby passing the goods through a bath having an alkaline .action.

The fastness properties of the dyeings obtained are surprisingly good,especially when-consider yielding metal. There may also be used asparentmaterials water-soluble azo-dyestuffs containing already metal incomplex union.

By the new process it is possible to obtain, in a relatively simple wayand without the fiber being damaged, fast dyeings on animal fibers or onnatural or artificial cellulose fibers and, especially, on mixed fibers.It is surprising that the dyeings obtainedby diazotizing theazo-dyestufis on the fiber and coupling them in "a feebly alkaline 'bathhave a very good fastness to rubbing, without the intermediate rinsingbaths,

usually applied in dyeing with diazotizing dyestuffs between .dyeinganddiazotizing or between diazotizing and coupling being inserted wherebythe dyeing .process is greatly facilitated for the dyer.

Mixed fibers from artificial silk staple fiber and wool have, forinstance, hitherto been dyed by applyingto the mixed fiber, in a neutralbath, a diazotizing dyestufl and an acid wool 'dyestufi stable todiazotizing, then rinsing-the material, I

-diazotizing, rinsing and developing the dyeing'by means of a developer,such as beta-naphthol.

This process may now be conducted in a considerably simpler way by usingaccording to the r'ir'esent invention an azo-dyestuff having an affinity--for cotton and containing an amino- '-group-capable of beingdiazotized and a hydroxyl group rendering coupling possible, applyingthis "dye'stufi, together with an acid -wool dyestufi stable todia'zotizing, to the mixed fiber, diazotizing the dyestufi-on the fiber,centrifuging the material and-causing self-coupling by addition -of somealkali to the subsequent rinsing bath,

and thenrinsing again.

Mixtures of animal-fibers, such as woo1,-with artificial :or natural.cellulose fibers may also be dyed' uniformly with one dyestuff by usingwatersoluble azmdyestuffs containing an amino-group capable of beingdiazotized' and a hydroxylwgroup rendering coupling possible, which havean affinity for both kinds ioffibersi Practically tone-intonedyeingsmay, for instance, be obtained on mixtures of wool and viscose staplefiberor other regenerated celluloses by applying to the tfiber,

V in a :feebly alkaline, neutral or feeblyacidrbath at raisedtemperature, for instance, ,a .watersoluble azoadyestuffof the followinggeneral con- ,stitution nonv wherein R1 stands for an aryl radical oragrouping of several aryl radicals which may be connected with eachother by members, such as ,-N=N- NHCO, -NH-CO-NH- CH2'.', NH- and thelike, and R2 ,means hydrogen or a substituent, then squeezing orcentrifuging the material, diazotizingthe dyestufi' on the fiber anddeveloping the dyeingby treatment with .anagent having a feebly alkalineaction. In an analogous manner the water-soluble azo-dyestuffsobtainableby coupling a diazotized amino-naphthol oramino-naphthol-sulphonic acid with an aminophenyl-methyl-pyrazolone ora; substitution product thereof 'may, for instance, also be developedon-thefiber with production of "fast dyeings.

Further-more, --mixed fibers from 'wool and viscose staple fiber orcuprammonium staple fiber may be dyed by the new process by applying tothe fiber a water-soluble mono-azo-dyestufi containing an amino-groupcapable of being diazotized and a hydroxyl group rendering couplingpossible together with a water-soluble 'disor poly-azo-dyestuif havingan aifinity for cotton and containing an amino-group capable of beingsodium'carbonate, rinsed cold and hot and then dried. A black dyeing ofgood fastness properties is obtained.

(2) 1 kg. of mixed yarn from 30 parts of cuprammoniunrr staple fiber.and'IOparts of W001 is treated for one hour at 85 C. with 24 liters ofwater containing 30 grams of the sodium salt of the azo-dyestuffobtainable by coupling diazotized diazotized and a hydroxyl grouprendering coun pling possible, then diazotizingibothdyestufis on thefiber and causing selfcoupling' by at'reatment with an agent having analkaline action. If the dyestuffs are suitably selected, tone-intonedyeings or mixed shades 'may thus be obtained.

The preceding statements characterize some possibilities of applying thenew .process.- The.

temperature during the dyeing process depends on the class of dyestuffsused and on the desired effect. .erably, conducted in the. cold or at aslightly fraisecl temperature, by means of a nitrite and an,acid, suchas hydrochloric acid, sulfuric acid,

formic acid and the like, wetting agents being, if desired, added to thebath, in order toimprove vthelwetting efiiciency in the subsequent bathhaving'an alkaline action. The dyeing is developed either in a freshbath by means of dilute mentwith washing agents, such assoap or thereactionproduct; from mols of ethylene-oxide and 1 mol. ofisooctyl-phenol.

The following examples illustrate the invention, the parts being byweight, unless otherwise stated:

(1) "1kg. of mixed yarn from 30 parts of viscose staple fiber and 70parts of wool is treated, for one hour at 75 C., with 50 grams of thesodium salt of the azo-dyestufi, obtainable by coupling diazotized1-amino-2-ch10ro-4-nitr0- benzene in an acid medium with2-amino-5-hydroxynaphthalene-7-sulfonic acid and subsequently reducingthe product obtained, and 80 grams of ammonium sulfate in 24 liters ofWater. 600 grams of sodium sulfate dissolved in 6 liters of cold waterare then added and the material is treated for aiurther hour at 60 C.,centrifuged and introduced into a' cold bath containing per 30 liters ofWater After diazotization for half an hour the materialis centrifugedand developed for half an hour in abath containing per 30 liters of coldwater Ammonia of per cent. strength cc 80 'Reaction product fromethylene-oxide and V 'octodecyl alcohol grams 10,

The material is rinsed. cold, treated at 40 Crwith a solution containingper liter-0.1 gram of the reaction product from 10 mols oiethylene-oxide and-l molpf isooctyl-phenol and 0.5 gram of Thediazotization on the fiber is pref-' of .watercontainingtifl grams ofammonium sulfate and grams of the sodiumsaltof the, am-

benzene, diazotizing again and coupling the diazo2-amino-S-hydroxynaphthalene-l-sulfonic acid with 1-(4f-aminophenyl)-3-methyl-5-pyrazolone. 600 grams of sodium sulfate dissolved in 6liters of cold water are then added and the material is treated foranother hour at about C., centrifuged, diazotized and developed asindicated in Example 1; rinsed cold and hot and then dried. A dark-browndyeing of good fastness properties i is obtained.

(3) 1 kg. of a'mixed fabric from 50 parts of viscose staple fiber and 50parts of wool is treated, for one hour at C. to C., with 24' litersdyestuff obtainable by coupling, diazotized lamino- 4 (4 -ni trcbenzoy1)-aminobenzene, ;in an acid medium with 2*amino-5-hydroxynaphtha-1ene-7-sulfonic acid and subsequently reducing the product obtained, and30 gramsrof the sodium salt of the azo-dyestufi obtainable by couplingdiazotized 2-amino-8-hydroxynaphthalene-6-sulfonic acid with1-.amino-2-methoxy-51=methylcompound. in an alkaline medium withZ-amino- 8 hydroxynaphthalene 6 sulfonic acid; gramsof sodiumsulfatedissolved in'6 liters'of cold water are then added and thegmaterial istreated for another hour at 70 C.1to 75 C.., then centrifuged,diazotized and developed in an amand dried.

A black dyeing of good fastness properties is obtained;

(4;) A-mixed fabric consisting of 30 per cent of viscose artificial silkand 70 per cent. of wool is treated, forv half an hour at 90 C., in abath moniacal bath as indicated in Example 1, rinsed =-containing 5 percent, of the disazo-dyestufi of the following formulaz H OH HzN SOaNaNaOaS I I by combining-one molof tetra zotized 4;.4'-.dia minodiphenylwith one mol oil-amino- 5-hydroxynaphthalene-7-sulfonic .acid in analkaline solutionand one mol of 1.5-dihydroxynaphthalene-3.7-disulfonicacid), 20 per cent. of

Glaubers. salt being added to the bath. .5. per

cent.,of acetic acid are then added and the material isdyed for anotherhalf hour at 90. C.

'(The percents are. calculated.upontheweight of the fiber.) Afterrinsing for a short time; the fabric is, diazotized for .half an, hourin a'cold bath containingiper liter 2 grams of sodium nitrite, 5 cc. ofhydrochloric acid of '35 per; cent. strength and 20 grams of sodiumchloride, rinsed again and thentreated for a quarter of an hour atroom-temperature in a bath containing per liter 2 grams of sodiumbicarbonate and subsequently soaped. The coupling may also beeffectedin-the diazo-tizing-bath itself by adding thereto sodium.bicarbonate until, the reaction is feebly alkaline. ,By this" treatmentthe. direct red-violet tintturns to a deep brown-violetshade 'ofconsiderably better fastness properties; j 1

v (5) A skein or fabric from viscose artificial silk is dyed for onehour at 80 'C. with 5 per cent of thedyestufi of thefollowingconstitutionz C1 Cl H2N S OaNa (obtainable .by combiningmono-diazotized 2.6-

(obtainable by combining diazotized'Q-aminmaacetyloxynaphthalene-G-sulionicacid with 2- amino 8hydroxy-naphthalene=6sulionic acid and eliminating the acetyl-group) 2per cent; of 5 sulfuric acid being added. By the 'diazotization asdescribed in Example 4, .a violet-black dyeing is obtained, the fastnessproperties of which are essentially improved. In a similar manner silkmay be dye-d with this dyestufi and then aftertrea-ted, similar dyeingsbeing obtained.

In a corresponding manner many of the dyestuffs named as examples in thedisclosure may be applied to mixed fabrics from woolza'nd viscose 5artificial silk and their iastness properties maybe improved bydiazotizing and coupling them on the fiber. Thus, for instance, theazzo-dyestufi of the following formula: 1

some

NH: OH

some

dichloro-1.4-diaminobenzene in an acid solution with2-amino-5-hydroxynaphthalene-'lsu1fonic acid), while adding per cent. ofsodium chloride. (The percents are calculated upon the weight of thefiber.) A reddish-brown dyeing is obtained which, by the process ofdiazotizing and coupling on the fiber as described in Example 4, turnsto a violetish-brown tint of considerably improved fastness properties.

If the above-named dyestuff is exchanged for the following dyestuff:

C O NH N=N -Q HzN- SOaNa (obtainable by combining diazotized2.6-dichloro- 1-amino-4- (3-nitrobenzoylamino) -benzene in an acidsolution with 2-amino-5-hydroxynaphthalene-l-sulfonic acid andsubsequently reducing the nitro-group) there is obtained by directdyeing a red tint which, when after-treated as described in Example 4,turns to a faster bluish-red tint.

(6) W001 is treated for one hour .in a boiling bath containing 5 percent. of the dyestufi' of the following formula:

S OaNa 80 :Na

SOaNa is less suitable for the production of uniform dyeings on mixedfabrics, since the shades; of the after-treated dyeings on wool andviscose artificial silk do not completely correspond which, however, maybe desirable under certain circumstances for the production of effects.This dyestufi may also be applied to cotton or viscose artificial silkand the dyeing obtained may-them be converted by after-treatment into ared-violet. shade of considerably enhanced fastness properties. f

(7.) A mixed fabric consisting of per cent. of viscose artificial silkand 70 per cent. of wooli is dyed for 1 hour at 70 C. with EO'percent ofsodium sulfate and 8 per cent. of the. dyestufl of the followingconstitution:

SONa ooNH 3 (obtainable by coupling diazotizcd l-aminohacetylaminobenzene in an alkaline solutionv with2-amino-5-hydroxynaphthalene-'l-sulfonic acid, transforming the productobtained into the 2'- hydroxynaphthalene-3-carboxylic acid amide andsplitting off the acetyl-g-roup, or by coupling diazotized p-nitranilinewith 2-amino-5-hydroxynaphthalene-'l-sulfonic acid, transforming theproduct obtained into the z hydroxynaphthalene-3-carboxylic acid amideand subsequently reducing thenitrO-Q'lfoub); The material is then with1-amino-8 hydroXynaphthalene-3.6-disulsqueezed or. rinsed for a shorttime and subsefonic acid; transforming the product obtained quentlytreated for half an hourin a diazotizinginto the zhydroxynaphthalene-3-carboxylic acid :tfrite', 5 cci of hydrochloricacid of ,35 per cent. 5 group). js ltren'jgthand'20 gr'ams'olf sodiumchloride. The Fast black-brown tints are obtained by using material; isrinsed again for a short time and in an analogous manner the dyestuff ofthe folf-th'en treated for a quarter of an hour ina bath lowingconstitution: I

contain-mg per liter 2 grams of sodium bicarbon- -at iis in 10 Thecouplingmay' also be effected in the diazo- -tizing-bath itself byadding sodium bicarbonate CH3 "-until. the reaction is feebly alkaline.r l Fast'black dyeingsare obtained by using under tlngsame' conditionsthedyestuff of the following 15 .cons tu n=. Y a I CH3 1 1; 1 v(obtainable by coupling diazotized 5-amino-4- OH l sloiNa 1methoxy-2-nitro l-methylbenzene in an alkaline CONE solution with2-amino-5-hydroxynaphthalene-7- 20 sulfonic acid, transforming theproduct obtained 7 7 7 7 into the 2-hydroxynaphthalene-3-carboxylic acidamide and subsequently reducing the nitro- I I p N group). The fastnessto light of the dyeings a I N .may be improved by a treatment with salts01 25 metals capable of forming complex compounds I (for instance coppersalts) on the fiber before or f I n v after 'diazotizing and coupling orduring the coupling reaction. It is also possible to start directly fromthe metal complex compounds of the p I 30 'dyestuff made in-su'bs'tance.r

- 2 The following table illustrates the shades of (obtainable bycoupling diazotized 1-amino-4- a number of further dyeings obtainable bythis acetylaminonaphthalene in an alkaline solution invention:

SOsNa Shade on mixed fibers from i Parent dyestuff v artificial silkstaple fiber I 5 and wool I acid 1 l-amlno-i-mtrobenzene2-ammo-5-hydroxy-naphthalene-7-sulfonic acid, reduced Reddish-black.

aci v i k c -2- '1-amino-3-'nitrobenzene'2-amino;5-hydroxy-naphthalene-7-sulfonic acid, reduced Garnet-red-brown.

. 2hydyogy4-nitrobenzene 2-amino-5-hydroxynaphthalene-7-sulfonic acidreduced Black-violet, after-treated with a copper compound: l 7 black,after-chromed: black.

acid i i-e.mino-2-methoxy-4-nitrobenzene2-amino-5-hydroxynaphthalene-7-sull'onic acid,reduced Currant,after-treated with R i, V v I I V 'a copper compound: blacki v 1 ralkaline 1 acid Y 5 =1-amino-4-n1trobenzene2-am1no-5-hydroxynaphthalene-7-su1fonic acid 2-phenylamino-5-hy- Black,after-treated with a d a copper compound: black,

droxynaphthalene-?-su1ionic acid, reduce after-chromed: black.

a f a 1 acid i I {I1 'l-angno-chloro-4-nitrobenzene-2-amino-5-hydroxynaphthalene-7-sultonic acid, 'ben'zoylated andReddish-black.

reuce. I

v ,v a acid 7- 1-amino-3-nitrobenzeneZ-phenylamino-5-hydroxynaphthalene-7-sulfonic acid, reducedReddish-bmwn. "'iiac 4 1 3 Laminai-nitrobenzene 2-a1nino5-hydroxynaphthalene-Fsulfonic acid, benzoylated and reduced...Reddish-black.

Y 9 1-amino-3-nitrobenzene, 2-amino-5-hydroxynaphthalene-7-sulfonicacid, benzoylated and reduced Br0wnred.

10 2-amino-5-hy droxynaphthalene-7-sulfonlc acidl-(3-aminophenyl)-3-methyl-5-pyrazolone Covered red.

11 2-amino-5-hydroxynaphthalene-7-sulionic acidl-(3-aminophenyl)-5-pyrazolone-3-carboxylic acid; Bordeaux 122-amino-8Fhy droxynaphthalene-fi-sulfonic acid l-(3-aminophenyl)-5-pyrazolone-3-carboxylic acid Red-brown.

13 1-amino-5-hydroxynaphthalene-7-sulfonic acidl-(4-axni1'1opheny1)-3-methyl-5-pyrazolone Brownish garnet,

14 l-amino-5-hydroxynaphthalene-7-sulfonic acidl-(3-aminophenyl)-3-methyl-5-pyrazolone s Covered red.

15 1-amino-5-hydroxy naphthalene-7-sulfonic acid1-(3-aminophenyl)-5-pyrazolone-3ecarboxylic acid Bordeaux red.

17 Z-amino-8-hydroxynaphthalene-6-sulfonic acidl-arnino-3.5-dimethylbenzene, condensed with. 3-nitro-4- Do.

methoxybenzoyl-chloride and reduced. 7 v i 1. 1:- i I 182-amino-5-hydroxynaphthalene-7-sulfonic acid Lamina-3.fidimethylbenzene, condensed with 3-nitro-4- Vivid red-brown.

methoxybenzoylchloride and reduced. 1 I

l9 2-amino-5-hydroxynaphthalene1-(3-aminophenyl)-5-pyrazolone-S-carboxylic acid -.s Orangebrown.

20 2-amino-8-hydroxynaphthalenel-(3-aminophenyl)-5-pyrazolone-3-carboxylic acid Copper-brown,

21 1-amino-5-hydroxynaphtha1ene-7-sulfonic acidl-amino-3-methyl-firrnethoxybenzene, condensed with Bordeaux.

4-nitrobenzoylchloride and reduced. 2 s 1 22rl-aminoefi-hydroxynaphthalene-7-sulfonic acidl-amino-3-methyl-fi-methoxybenzene, condensed with Brown.

'3-nitro-4-methoxybenzoylchloride and reduccdl 2-(-aminobenzoyl-4-aminobenzoyl-amino)-5-hydroxynaphthalene-7-sulfonic acid1-a1nino-2- D0. Y methoxy-5-methylbenzene. p r 242-amino-5-hydroxynaphthalene-7-sulfonic acid 1-ammo3-methyl-6-methoxybenzene, condensed with Garnet.

1 '4-nitrobenzoylchloride and-reduced. 252-amino-5-hydroxynaphthalene-7-sulfonic acid 1-amino-3-methyl-fi-inethoxybenzene, condensed with Brown.

3-nitro-4-methoxybenzoylchloride and reduced. j Z262-amino-8-hydroxynaphthalene-S-sulfonic acid?)1-(3-aminophenyl)-3-methyl-5'pyrazolone Brown-red. ,27.2-amino-7-hydroxynaphthalene l-(3'-aminophenyl)-5pyrazolone-3-carboxylic acids" R d,

28 2-a1nino-8-hydroxynaphthalene-fi-sultonio acid nl{-a1rninonaphthalene Oleves acid; l Dark-brown. II 3' it v "5;. ii. 7 a311-116, 1 r I I 29' l-amino-7-hydroxynaphthalene Cleyes acid2-amino-8-hygroxy-naphthalene-6-sulfonic acid- Dark-blue.

i l v .7 l, .v 3301 V v 1-amino-4-nitrobenzene 7-).1-ainino-2-methoxy-5-methylbenzene 2-amino-5-hydroxynaphthalene-7-Dark-brown.

sulfonic acid, reduced.

bathjcontaining perljliter 2 grams of sodiumniamide and subsequentlysplitting off the acetyl- 1. The process which comprises applying to theand treating the dyeing with an agent yielding.

fiber an alkali metal salt-of a water-soluble azodyestufi containing inthe molecule an aminogroup capable of being diazotized and a'hydroxylgroup rendering coupling possible, thendla'zotizing the dyestuifon thefiber and causing it to combine with itself by an alkaline treatment.

2. The process which comprises applying to the fiber an alkali metalsalt of a water-soluble azo-dyestuff containing in the molecule anamino-group capable 'of being diazotized and a hydroxyl group renderingcoupling possible, then diazotizing the dyestuff on the fiber andcausing it to combine with itself by adding to the diazobath an agenthaving an alkaline action,

Shade on mixed fibers from Parent dyestufl artificial silk staple fiberand wool 72 1-amino-8-hydroxynaphtha1ene-3.fi-disulfonic'acid ClevesacidL- 'Violet-brown. 73 1-amino-5-hydroxynaphtha1ene-7-sulfonic acid)1-amino-2-methoxy-5-methylbeu Red-brown. 74 l-amino-7-hydroxynaphthaleneClevesacid..;; r Dark red-brown. 752-amino-8-hydroxynaphthalene-6-su1fonic acid LaminonaphthaleneBlackbrown. 76 2-amino-5-hydroxynaphthalene-7-su1fonicacid-Xl-aminonaphthalene; Brown. 772-(4-aminobeuzoylamino)-8-hydroxynaphthalenet-sulfonic acid l-amino-3.-dimetl1ylbenzene Garnet; 78 2-amino-8-hydroxynaphthalene-fi-sulfonicacid l-amino-3.5-d1methy1benzene Violetish black. 792-amino-5-hydroxynaphthalene-7-sulfonic acidl-amino-B.fi-dimethylbenzene 0. 802-amino-8-hydroxynaphthalene-fi-sulfonic acid meta-amino-acetanilidenViolet-brown; 81 2-amino-8-hydroxynaphthalene-fi-sulfonic acidl-amino-2-methoxy-fi-methylbenzene I Reddish black.

82 1-amino-8-hydr0xynaphthalene-3.6-disulfouic acid1-(3-am'inophenyl)-5-pyrazolone-3-carboxyl1c ac1d.'- Copper-red. I. -aciI j 83 1-aminc-2.6-dichloro-4-nitrobenzene-+ 2- amino-5-hydroxynaphthalene-7-sulfonic acid, reduced Reddish black.

acl 84 l-amino-2.5-dimethoxy-4-nitrobenzene2-amin0-5rhydroxynaphthalene-7-sulionic acid, reduced" Currant.

- acl v 1 85 1-amino-2.5-diethoxy-4-nitrobenzene 2-amino-5-l1ydroxynaphthalene-7-sulfonic acid, reduced Do.

; 86 l-amino-3-(4'-nitrobenzoyl)-aminoba3zene--2-amino-5-hydroxynaphthalene-7-sulfonic acid, reduced Garnet.

. aci 87 Lamino-2-methyl-4-nitrobenzene2-aminozi5-hydroxynaphtha1ene-7'su1lonic acid, reduced Black.

r .aci V 88 1-amino-2-methoxy-5-chloro 4-nitrobenzener 2-amino-5hydroxynaphthalene-7-sulfonic acid, reduced" Black-violet; afteritreated lwlithka copper compound: V .T f f I a0. 891-(3-aminophenyl)-3methyI-5-pyrazolone 4.4-diamino-diphenyl-sullgolficacid 1.3-dihydroxybenzene Orange-brown.

1. I aine 90 l-amino-S-hydroxynaphthalene 2-amino-7-hydroxy-naphthalene2-amino-5-hydroxynaphtha- Violet-brown.

lene-7-su1fonic acid. I 7 1-amino-8-hydrgxynaphthalene2-(4-ammobenzoyl-4-ammobenzoyl-am1no)-5-hydroxynaphthalene- Red-brown.

7-sulfonic aci I 92 l-amino-S-hydroxynaphthalene'a 2-(3-aminobenzoyl-4Faminobcnzoyl-amino)-5-hydroxynaphthalene-7- Do.

sulfonic acid. H l I I a V We claim: V n then diazotizingthe dyestuff'onthe fiber, causing it to combine with itself by an alkaline treatmentmetal, V

6. The processwhich comprises applying to mixed fibers from artificialsilkjstaple fiber and wool an alkali metal .salt of the water-solubleazo-dyestuif obtainable" by coupling diazotized1-amino-2-chloro-4-nitrobenzene in an acid medium with2-amino-5-hydroxynaphthalene-7-sul- 3. The process which comprisesapplying to the I fiber an alkali metal salt of a water-solubleazodyestufi containing in the molecule an aminogroup capable of beingdiazotized and a hydroxyl group rendering coupling possible, thendiazotizing the dyestufl on the fiber and causing it to combine withitself by passing the fiber through a bath having an alkaline action.

4. The process which comprises applying to the fiber an alkali metalsalt of a water-soluble azo-dyestuff containing 2-amino 5hydroxynaphthalene-'l-sulfonic acid as azo-component and inthe'diazo-comp'onent an amino-group'ca pable of being diazotized, thendiazotizing the dyestufi on the fiberand causingit to combinewith itselfby an alkaline treatment.

5. The process which comprises-applying to'- mixed fibers fromartificial silk staple fiber and wool an alkali metal salt of thewater-soluble azo-dyestuff obtainable by coupling diazotized 1-amino-2ehydroxy-4-nitrobenzene in an acid medium with 2-amino-5hydroxynaphthalene-Z-sul fonic acid and reducing the product obtained, 5

corresponding with the followingformula:

Hogs NH:

fonic acid and reducing the product obtained, corresponding with thefollowing formula;

v 'OH thenl diazotizing the dyestufi on the fiber and causing it tocombine with itself by an alkaline treatment. x

'7. Theprocess which comprises applying to .mixedfibers from artificialsilk staple fiber and corresponding 7 with the ,following formula:

' then diazoti'zing the dyestuif on the fiber, causing it to combinewith itself by, an alkaline treatment and after-chroming the dyeing.

8. The process which comprises applying to "mixed fibers from'artificial silk staple fiber and woolf an alkali metal salt of. thewater-soluble azo dyestufi obtainable by coupling diazotized 1- HOaSthen diazotizing the dyestuff on the fiber and causing it to combinewith itself by an alkaline treatment.

9. The process which comprises applying to mixed fibers from artificialsilk staple fiber and wool an alkali metal salt of the water-solubleazo-dyestufi obtainable by coupling diazotized 1- aminoi-nitrobenzene inan alkaline medium with 2-amino-5-hydroxynaphthalene-7 sulfonic acid,diazotizing the dyestuff obtained, coupling the diazo-compound in anacid medium with 2- phenylamino-5-hydroxynaphthalene- 7 sulfonic acidand reducing the product obtained, corresponding with the followingformula:

then diazotizing the dyestuff on the fiber, causing it to combine withitself by an alkaline treatment and after-treating the dyeing with acopper-compound.

WERNER KIRST. WOLFGANG ALT. HANS KRZIKALLA.

